Bug 2523560 (CVE-2026-79676)

Summary:	CVE-2026-79676 nltk: NLTK: Information disclosure via path traversal with symlink bypass
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	anpicker, bparees, dschmidt, ebourniv, hasun, jfula, jlanda, jowilson, kshier, nyancey, ometelka, ptisnovs, sbunciak, simaishi, stcannon, syedriko, teagle, xdharmai, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in NLTK. This path traversal vulnerability allows attackers to bypass security measures by using symbolic links within trusted data roots. By staging specially crafted symlinked corpus files, an attacker can disclose sensitive information from outside the intended data directories. This could lead to unauthorized access to confidential data.	Story Points:	---
Clone Of:		Environment:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2524985, 2524986
Bug Blocks:

Description OSIDB Bzimport 2026-08-25 15:34:12 UTC

NLTK versions before 3.10.3 contain a path traversal vulnerability in corpus readers that reopen root-derived paths using built-in open() instead of nltk.pathsec.open(), allowing symlinks to escape trusted roots. Attackers who stage symlinked corpus files under a trusted data root can disclose outside-root content through normal corpus reader methods like channels(), domains(), and synonyms().